Process for semi-permanent hair straightening and aftercare of the hair

ABSTRACT

The present invention relates to a process for semi-permanent hair straightening and aftercare treatment and to a kit of compositions for use in this process. In the process of the present invention, the hair is firstly subjected to a straightening treatment using a straightening composition comprising at least one carboxylic acid of the formula (I): R—CO—COOH defined below and/or a hydrate thereof and/or a salt thereof. Then, a specific cleansing composition and/or a specific conditioning composition comprising at least one carboxylic acid of the formula (I): R—CO—COOH defined below and/or a hydrate thereof and/or a salt thereof are used as aftercare products in order to improve durability of the straightening effect.

FIELD OF THE INVENTION

The present invention relates to a process for semi-permanent hair straightening and the aftercare treatment of the hair and to a kit of compositions for use in this method.

BACKGROUND OF THE INVENTION

A known method for straightening curly or frizzy hair involves the use of straightening irons. The high temperature of the iron leads to a breakage of hydrogen bonds in the keratin of the hair, achieving a temporary straightening. The hydrogen bonds are formed again by the action of moisture, so that the hair reverts back to its original shape over the time because of air humidity, and the straightening effect vanishes after washing the hair.

The shape of the hair is largely determined by the disulfide bonds linking two cysteine moieties of the hair keratin. In order to achieve a more permanent shaping of the hair, known methods involve the cleavage of the disulfide bonds by the action of a sulfide- or thio group containing reducing agent. After the hair has been brought into the desired shape, new disulfide bonds are formed by applying an oxidizing agent such as hydrogen peroxide, thus fixing the shape of the hair. The use of such agents, however, may cause damage to the hair.

As an example for this kind of hair shaping treatment, reference is made to GB 1 416 564, describing reducing compositions comprising thioglycolates or thiolactates as reducing agents and fixing compositions comprising hydrogen peroxide as an oxidizing agent. The reducing compositions may further comprise a salt of glyoxylic acid as a buffering agent.

As an alternative to the above-described two-step reduction and oxidation process, the disulfide bridges can be cleaved by the action of an alkaline agent such as sodium hydroxide at a pH of about 11 or higher. Under these conditions, the disulfide (or cystin) moiety can undergo a disproportionation reaction under the elimination of sulfur, and is cleaved into an alpha-beta-unsaturated dehydro-alanine moiety and a cysteine moiety. After the hair has been brought into the desired shape, the dehydro-alanin moieties and the cysteine moieties form thioether bonds and combine to lanthionine, stabilizing the straightened state of the hair. Since the disulfide or cystin moieties are converted into lanthionine moieties, this type of hair straightening process using an alkaline agent is also called lanthionization.

Both the two-stage reduction/oxidation method and the lanthionization method rely on a cleavage of the disulfide bonds and the formation of new bonds among the hair proteins, leading to an irreversible change of the shape of the hair. This means that these processes can achieve a permanent straightening, wherein the treated portion of the hair maintains its shape, and the straightening effect only vanishes because of the growth of the hair.

Recently, it has been found that α-keto acids such as glyoxylic acid, which are known as a buffering agent in cosmetic compositions, may have a semi-permanent straightening effect when used in combination with mechanical straightening means.

In this respect, WO 2011/104282 describes a process for semi-permanent hair straightening, which involves applying a composition comprising an α-keto acid onto the hair, leaving the composition in contact with the hair for 15 to 120 minutes, drying the hair and straightening the hair with a straightening iron at a temperature of 200±50° C.

Furthermore, WO 2012/010351 describes a treatment for semi-permanent straightening of curly, frizzy or wavy hair by applying a solution of glyoxylic acid in combination with mechanical straightening, using a straightening iron at a temperature of 20030° C. After the treatment, the hair is said to retain its shape for at least six consecutive washings.

EP 0685 219 describes a composition useful as a pre-treatment agent before subjecting the hair to a perm wave treatment, the composition comprising a film-forming cationic, anionic and/or amphoteric polymer, an amphoteric surfactant, an organic acid and a C2 to C4 alcohol, and being free of cationic surfactants.

SUMMARY OF THE INVENTION

The present invention is directed to a process, which comprises the following steps performed in this order:

-   (a) application of a straightening composition onto the hair, -   (b) leaving the composition on the hair for 1 to 120 minutes; -   (c) optionally rinsing off the hair; -   (d) drying the hair, -   (e) treating the hair with an iron having a surface temperature of     130 to 250° C., -   (f) optionally rinsing off and/or shampooing the hair and drying; -   (g) treating the hair with a one or both, preferably both of a     cleansing composition and a conditioning composition;     wherein     -   the straightening composition has a pH of 4 or lower and         comprises at least one carboxylic acid of the Formula (I) and/or         a hydrate thereof and/or a salt thereof;     -   the cleansing composition has a pH of 4 or lower and comprises         one or more surfactants selected from anionic, non-ionic and         amphoteric surfactants and at least one carboxylic acid of the         Formula (I) and/or a hydrate thereof and/or a salt thereof; and     -   the conditioning composition has a pH of 4 or lower and         comprises one or more conditioning components and at least one         carboxylic acid of the Formula (I) and/or a hydrate thereof         and/or a salt thereof:

R—CO—COOH  Formula (I)

wherein R is selected from hydrogen, COOH, CN, optionally substituted C₁-C₁₀ alkyl, optionally substituted C₂-C₁₀ alkenyl, optionally substituted C₂-C₁₀ alkynyl, optionally substituted C₃-C₁₀ cycloalkyl, optionally substituted C₆-C₁₀ aryl or a 5-10-membered, optionally substituted heteroaryl group, wherein the optional substituents of the alkyl group are selected from halogen, hydroxyl, amino and C₁-C₄ alkoxy, and the optional substituents of the other groups are selected from halogen, hydroxyl, amino, C₁-C₄ alkyl and C₁-C₄ alkoxy.

In the present invention, steps (a) to (f) refer to the straightening treatment and are carried out in direct succession, while step (g) refers to an after-treatment, which can be performed whenever it is desired to cleanse and/or condition the hair.

Another aspect of the present invention relates to a hair treatment kit, which comprises a straightening composition and at least one of a cleansing composition and a conditioning composition, wherein the straightening composition and the at least one of the cleansing composition and the conditioning composition comprise at least one carboxylic acid of the Formula (I) and/or a hydrate thereof and/or a salt thereof. Preferably, the kit comprises the straightening composition, the cleansing composition and the conditioning composition as defined above.

Yet another aspect of the invention relates to the use of a cleansing composition and/or a conditioning composition comprising at least one carboxylic acid of Formula (I) and/or a hydrate thereof and/or a salt thereof as an after-treatment composition for increasing the durability of a hair straightening treatment.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1: Photographs of the hair samples in the Test Example (from left to right)

-   -   (1) untreated frizzy hair before the treatment with the         straightening composition;     -   (2) hair treated with the straightening composition and         shampooed once with a conventional shampoo;     -   (3) hair treated with the straightening composition and         afterwards subjected to shampooing/conditioning for 10 cycles         with the comparative compositions comprising lactic acid;     -   (4) hair treated with the straightening composition and         afterwards subjected to shampooing/conditioning for 10 cycles         with the inventive compositions comprising glyoxylic acid.

DETAILED DESCRIPTION OF THE INVENTION

The above-described prior art methods using a compound such as glyoxylic acid in combination with straightening irons achieve a semi-permanent straightening of the hair. There is demand, however, for further improvement of the hair structure and manageability and an increased durability of straightening effect.

The present invention solves this problem by providing a method wherein, after a straightening treatment of the hair using a straightening composition comprising at least one carboxylic acid of the Formula (I) defined below and/or a hydrate thereof and/or a salt thereof, a specific cleansing composition and/or a specific conditioning composition are used as after care products in order to improve durability.

In the process of the present invention, the above-defined steps (a) to (f) achieve a semi-permanent straightening of the hair. Unlike permanent straightening, which refers to an irreversible change of the hair shape and is achieved by a cleavage of the disulfide bonds by a sulfur based reducing agent or by strong alkali followed by a fixing of the new shape by oxidation or lanthionine-formation, respectively, semi-permanent straightening means that the change of the shape of the hair is reversible, so that the straightened hair would return to its original shape after a certain number of washing cycles. When performing step (g) as an after-treatment after the semi-permanent straightening in accordance with steps (a) to (f), however, the straightening effect can be substantially prolonged.

1. The Straightening Composition

The straightening composition comprises at least one carboxylic acid of the following formula (I) as the active component:

R—CO—COOH  Formula (I)

wherein R is selected from hydrogen, COON, CN, optionally substituted C₁-C₁₀ alkyl, optionally substituted C₂-C₁₀ alkenyl, optionally substituted C₂-C₁₀ alkynyl, optionally substituted C₃-C₁₀ cycloalkyl, optionally substituted C₆-C₁₀ aryl or a 5-10-membered, optionally substituted heteroaryl group, wherein the optional substituents of the alkyl group are selected from halogen, hydroxyl, amino and C₂-C₄ alkoxy, and the optional substituents of the other groups are selected from halogen, hydroxyl, amino, C₂-C₄ alkyl and C₁-C₄ alkoxy.

As preferred examples, glyoxylic acid, pyruvic acid and 2-ketobutyric acid can be mentioned.

The carboxylic acid of Formula (I) may be comprised in the composition in its free acid form. The carbonyl group adjacent to the acid group of the acid may also be present in the hydrate form. Apart from the free acid form and the hydrate thereof, salts of the acid or the hydrate may also be used.

The hydrate of the acid of Formula (I) may be formed when providing the composition as an aqueous solution. For instance, glyoxylic acid (H—CO—COOH) in aqueous solution is almost quantitatively present as the hydrate (H—C(OH)₂—COOH). Besides, the hydrate may also condense to dimers.

A salt of the carboxylic acid of Formula (I) may also be used. As examples, alkali metal salts such as the sodium or potassium salt, and alkaline earth metal salts such as the magnesium salt or the calcium salt.

In the present invention, glyoxylic acid or a hydrate thereof is an especially preferred carboxylic acid of Formula (I).

The concentration of the at least one carboxylic acid of the Formula (I) and/or a hydrate thereof and/or salts thereof is in the range of 0.1 to 40%, preferably 0.5 to 30%, more preferably 1 to 25% and even more preferably 2.5 to 20% by weight, based on the total weight of the straightening composition.

The pH of the straightening composition is below or equal to 4.0, preferably in the range of 0.5 to 3.5, more preferably 1 to 3, more preferably 1 to 2.5, as measured directly and at ambient temperature (25° C.). The pH of the compositions may be adjusted using known alkaline solutions, preferably with sodium hydroxide solution.

As discussed above, conventional permanent hair shaping/straightening techniques are based on the re-organization of the disulfide bridges and involve a cleavage of the disulfide bonds either by using a sulfur-based reducing agent or an alkali agent, followed by the shaping of the hair and the formation of new bonds (i.e., disulfide bonds formed by the action of an oxidizing agent or thioether bonds, respectively). In contrast to these permanent straightening methods, the present invention does not utilize cleavage of the disulfide bonds and fixing the bonds in the new shape. Therefore, the straightening composition of the present invention does not require the presence of sulfur-based reducing agents, and preferably is free of sulfur based reducing agents. However, up to 2% by weight calculated to the total of the composition of sulfur based reducing agents does not disturb the straightening performance of the compositions. Therefore, the treatment composition has less than 2% by weight of sulfur-based reducing agents, and preferably is free of sulfur-based reducing agents.

The straightening composition may suitably comprise further ingredients such as surfactants and/or conditioning agents as defined below, and may suitably be in the form of a solution, emulsion, cream, gel, paste and/or mousse.

As the surfactants, one or more of the anionic surfactants, the non-ionic surfactants and the amphoteric/zwitterionic surfactants defined below in connection with the cleansing composition may be used. The concentration thereof may suitably be in the range of 0.1 to 20% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight, based on the weight of the straightening composition.

As the conditioning components, one or more of the silicones, the cationic polymers, the oil components, the fatty alcohols and the cationic surfactants defined below in connection with the conditioning composition may be used. The concentration thereof may suitably be in the range of 0.1 to 20% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight, based on the weight of the straightening composition.

For improving the feel of use, it is preferable to include a silicone compound as a conditioning component into the straightening composition.

Besides, the straightening composition may comprise further ingredients conventionally used in the field of cosmetics, such as preservatives, chelating agents, stabilizers, oxidation inhibitors, plant extracts, ultraviolet absorbers, vitamins, dyes, and fragrances.

Furthermore, the straightening composition may be formulated as a one-part composition, or as a two-part composition comprising the parts A and B, which are stored separately and mixed prior to the application to the hair, wherein part A comprises the carboxylic acid of formula (I) and part B comprises at least one of a fragrance, a surfactant or a conditioning component. Improved fragrance stability is observed with two-part compositions.

2. The Cleansing Composition (Shampoo)

There are no particular limitations with respect to the cleansing composition (shampoo) used in the present invention, as long as it comprises at least one carboxylic acid of the Formula (I) defined above and/or a hydrate thereof and/or a salt thereof.

The concentration of the at least one compound of Formula (I) in the cleansing composition is preferably in the range of 0.01 to 5%, more preferably 0.1 to 5%, more preferably 0.2 to 5%, even more preferably 0.2 to 4%, yet more preferably 0.2 to 3% and still more preferably 0.25 to 2.5% by weight, based on the weight of the cleansing composition. Generally, a content of the compound of 0.2% or more is preferable in view of maintaining the straightening effect.

For providing the cleansing effect, the cleansing composition comprises one or more surfactants selected from anionic, non-ionic and amphoteric surfactants, typically at a concentration in the range of 5 to 50% by weight, based on the weight of the total composition. Preferably, the total surfactant concentration in the cleansing composition is in the range of 7.5 to 30%, more preferably 10 to 25% by weight, based on the weight of the cleansing composition.

Preferably, the cleansing composition of the present invention comprises at least one anionic surfactant, preferably of an alkyl ether sulphate type. It is even more preferable that the cleansing composition of the present invention also comprises at least one nonionic surfactant and optionally at least one amphoteric surfactant in addition to the anionic surfactant.

In a further preferred embodiment, the cleansing composition comprises at least one anionic surfactant, preferably of the alkyl ether sulphate type, at least one non-ionic surfactant, preferably an alkyl polyglucoside and at least one amphoteric surfactant, preferably of the alkyl amido alkyl betaine type. More preferably, the composition additionally comprises an acyl amino carboxylic acid surfactant, preferably sodium lauroyl glutamate, further to the anionic, the non-ionic and the amphoteric surfactant.

In order to improve the feel of use, the cleansing composition of the present invention may preferably also comprise one or more conditioning agents, preferably selected from cationic polymers and silicone compounds as defined below in connection with the conditioner.

When adding one or more conditioning agents, the concentration thereof may suitably be in the range of 0.1 to 20% by weight, preferably 0.2 to 10% by weight, more preferably 0.5 to 5% by weight, based on the weight of the cleansing composition.

The pH value of the cleansing composition is 4 or lower. For avoiding the risk of skin irritation and improving the safety of use as well as storage stability, it is preferable that the pH is higher than 1.5. Therefore, the pH value preferably is in the range of 1.5 to 4.0, more preferably 2 to 3.5 and even more preferably 2.5 to 3.0. The pH value of the composition is measured directly and at ambient temperature (25° C.), and may be adjusted as necessary.

Besides, the cleansing composition may comprise further ingredients conventionally used in the field of cosmetics, such as preservatives, chelating agents, stabilizers, oxidation inhibitors, plant extracts, ultraviolet absorbers, vitamins, dyes, and fragrances.

Anionic Surfactants

Preferably, the cleansing composition comprises one or more anionic surfactants suitably in a concentration from 1 to about 30%, preferably 2 to 20%, more preferably 2 to 15% and even more preferably 3 to 10% by weight of the cleansing composition.

There are no particular limitations as to the type of the anionic surfactant. Respective examples include anionic surfactants of the sulphate, sulphonate, carboxylate and alkyl phosphate type.

As examples for sulphate type anionic surfactants, C₁₀-C₁₈-alkyl sulfates and alkyl ether sulphates can be mentioned. Preferable examples for anionic surfactants are those customarily used in shampoo compositions, for example, the known C₁₀-C₁₈-alkyl sulfates, and in particular the respective ether sulfates, for example, C₁₂-C₁₄-alkyl ether sulfate, lauryl ether sulfate, especially with 1 to 4 ethylene oxide groups in the molecule, monoglyceride (ether) sulfates, fatty acid amide sulfates obtained by ethoxylation and subsequent sulfatation of fatty acid alkanolamides, and the alkali salts thereof.

As regards the alkyl phosphate type anionic surfactants, the salts of long-chain mono- and dialkyl phosphates, which constitute mild, skin-compatible detergents, may preferably be used.

Further anionic surfactants useful within the scope of the invention are α-olefin sulfonates or the salts thereof, and in particular alkali salts of sulfosuccinic acid semiesters, for example, the disodium salt of monooctyl sulfosuccinate and alkali salts of long-chain monoalkyl ethoxysulfosuccinates.

Suitable surfactants of the carboxylate type are alkyl polyether carboxylic acids and the salts thereof of the formula

R₁—O—(C₂H₄O)_(n)—CH₂COOX,

wherein R₁ is a C₈-C₂₀-alkyl group, preferably a C₁₂-C₁₄-alkyl group, n is a number from 1 to 20, preferably 2 to 17, and X is H or preferably a cation of the group sodium, potassium, magnesium and ammonium, which can optionally be hydroxyalkyl-substituted, as well as alkyl amido polyether carboxylic acids of the general formula

wherein R₁ and X have the above meanings, and n is in particular a number from 1 to 10, preferably 2.5 to 5.

Such products have been known for some time and are on the market, for example, under the trade name “AKYPO®” and “AKYPO-SOFT®”.

Also useful are C₈-C₂₀-acyl isothionates, alone or in admixture with other anionic surfactants, as well as sulfofatty acids and the esters thereof.

It is also possible to use mixtures of several anionic surfactants, for example an ether sulfate and a polyether carboxylic acid or alkyl amidoether carboxylic acid.

Further suitable anionic surfactants are also C₈-C₂₂-acyl aminocarboxylic acids or the water-soluble salts thereof. Especially preferred is N-lauroyl glutamate, in particular as sodium salt, as well as, for example, N-lauroyl sarcosinate, N—C₁₂-C₁₈-acyl asparaginic acid, N-myristoyl sarcosinate, N-oleoyl sarcosinate, N-lauroyl methylalanine, N-lauroyl lysine and N-lauroyl aminopropyl glycine, preferably in form of the water-soluble alkali or ammonium, in particular the sodium salts thereof, preferably in admixture with the above-named anionic surfactants.

The most preferred anionic surfactants within the meaning of the present invention are alkyl ether sulphates such as lauryl ether sulphate and aminocarboxylic acids such as lauroyl glutamate sodium salt.

Nonionic Surfactants

Preferably, the cleansing composition comprises one or more non-ionic surfactants, suitably at a concentration of 1 to 15%, preferably 1 to 10% by weight, based on the weight of the cleansing composition.

Preferable non-ionic surfactants are alkyl polyglucosides of the general formula

R₂—O—(R₃O)_(n)—Z_(x),

wherein R₂ is an alkyl group with 8 to 18 carbon atoms, R₃ is an ethylene or propylene group, Z is a saccharide group with 5 to 6 carbon atoms, n is a number from 0 to 10 and x is a number between 1 and 5.

These alkyl polyglucosides have recently become known in particular as excellent skin-compatible, foam improving agents in liquid detergents and body cleansing compositions.

Mixtures of anionic surfactants and alkyl polyglucosides as well as the use thereof in liquid body cleansing compositions are already known, for example, from EP-A 70 074. The alkyl polyglucosides disclosed therein are basically also suited within the scope of the present invention; as well as the mixtures of sulfosuccinates and alkyl polyglucosides disclosed in EP-A 358 216.

Further nonionic surfactant components may be present, for example, long-chain fatty acid dialkanolamides, such as coco fatty acid diethanolamide and myristic fatty acid diethanolamide, which can also be used as foam enhancers.

Further additionally useful nonionic surfactants are, for example, the various sorbitan esters, such as polyethylene glycol sorbitan stearic acid ester, fatty acid polyglycol esters or poly-condensates of ethyleneoxide and propyleneoxide, as they are on the market, for example, under the trade name “Pluronics®”, as well as fatty alcohol ethoxylates.

Further suitable nonionic surfactants are amineoxides. Such amineoxides are state of the art, for example C₁₂-C₁₈-alkyl dimethyl amineoxides such as lauryl dimethyl amineoxide, C₁₂-C₁₈-alkyl amidopropyl or -ethyl amineoxides, C₁₂-C₁₈-alkyl di(hydroxyethyl) or (hydroxypropyl) amineoxides, or also amineoxides with ethyleneoxide and/or propyleneoxide groups in the alkyl chain. Such amineoxides are on the market, for example, under the trade names “Ammonyx®”, “Aromox®” or “Genaminox®”.

Further nonionic surfactants useful in the cleansing composition according to invention are C₁₀-C₂₂-fatty alcohol ethoxylates. Especially suited are C₁₀-C₂₂ fatty alcohol ethers, the alkyl polyglycol ethers known by the generic terms “Laureth”, “Myristeth”, “Oleth”, “Ceteth”, “Deceth”, “Steareth” and “Ceteareth” according to the CTFA nomenclature, including addition of the number of ethylene oxide molecules, e.g., “Laureth-16”.

The average degree of ethoxylation is generally between 2.5 and 25, preferably between 10 and 20.

The most preferred non-ionic surfactants are alkyl polyglucosides such as decyl, cocoyl polyglucoside and ethoxylated fatty alcohols such as laureth-16.

Amphoteric/Zwitterionic Surfactants

As further surfactant component, the cleansing composition according to the invention can also contain amphoteric or zwitterionic surfactants, for example in a concentration from about 1% to about 15%, preferably from about 2% to about 10%, by weight, based on the weight of the total composition.

It has been found out that the addition of zwitterionic or amphoteric surfactants enhances foam feeling in terms of creaminess, foam volume and as well as skin compatibility is improved.

For achieving milder formulations, the cleansing composition preferably contains an anionic surfactant (preferably of the sulphate type) in combination with an amphoteric surfactant at a weight ratio in the range of 10:1 to 1:1, preferably 5:1 to 1:1.

As the amphoteric surfactants, known betaines such as alkyl betaines, fatty acid amidoalkyl betaines and sulfobetaines, for example, lauryl hydroxysulfobetaine may be used Long chain alkyl amino acids, such as cocoaminoacetate, cocoaminopropionate and sodium cocoamphopropionate and -acetate have also proven suitable.

In detail, it is possible to use betaines of the structure

wherein R₄ is a C₈-C₁₈-alkyl group and n is 1 to 3; sulfobetaines of the structure

wherein R₄ and n are same as above; and amidoalkyl betaines of the structure

wherein R₄ and n are same as above.

The most preferred amphoteric surfactants are alkyl betaines such as lauryl betaine or cocoyl betaine and alkyl amido betaines such as cocamidopropyl betaine.

3. The Conditioning Composition (Conditioner)

There are no particular limitations with respect to the conditioning composition (conditioner) used in the present invention, as long as it comprises at least one compound according to the above general Formula (I) and/or a hydrate thereof and/or a salt thereof.

The conditioning composition of the present invention is preferably a leave-in composition, which is not rinsed off from the hair after application onto either wet or dry hair. Alternatively, the conditioner may be a rinse-off conditioner which is rinsed off from the hair after application and leaving on the hair for a certain period of time.

Regardless of the type of application, the conditioner may be in the form of a solution, dispersion, emulsion, foam or gel. These compositions may be applied onto the hair simply by hand after rubbing into the hands and distributing them onto the hair homogeneously or by spraying onto hair either from a mechanical device or from a pressurized aerosol container.

The conditioner preferably comprises the compound of the above Formula (I) at a concentration in the range of 0.01 to 5%, more preferably 0.1 to 5%, more preferably 0.2 to 5%, even more preferably 0.2 to 4%, yet more preferably 0.2 to 3% and still more preferably 0.25 to 2.5% by weight, based on the weight of the composition. Generally, a content of the compound of 0.2% or more is preferably in view of maintaining the straightening effect.

In addition to the compound of Formula (I), the conditioner comprises one or more conditioning components. Examples of the conditioning component generally include cationic polymers, silicones, higher alcohols, organic conditioning oils (for example, hydrocarbon oil, polyolefin and fatty acid ester) and cationic surfactants. It is possible to use only a single type of conditioning component, or two or more in combination. The conditioning components adhere to the hair and improve the feel and the manageability.

Typically, the conditioner of the present invention comprises at least one conditioning component selected from cationic polymers, silicone compounds and cationic surfactants. In addition, the conditioner preferably comprises at least one oil component and/or a fatty alcohol as further conditioning components.

The concentration of the conditioning components is generally in the range of 0.1 to 90% by weight, based on the weight of the total composition. Preferably, the content of the conditioning components is in the range of 0.2 to 30 wt. %, more preferably 0.5 to 20 wt. %, based on the weight of the conditioning composition.

The conditioner of the present invention is preferably an aqueous composition and comprises at least 10% by weight of water, based on the weight of the total composition.

The pH value of the conditioning composition is 4 or lower. For avoiding the risk of skin irritation and improving the safety of use as well as storage stability, it is preferable that the pH is higher than 1.5. Therefore, the pH value preferably is in the range of 1.5 to 4.0, more preferably 2 to 3.5 and even more preferably 2.5 to 3.0. The pH value of the composition is measured directly and at ambient temperature (25° C.), and may be adjusted as necessary.

Besides, the conditioning composition may comprise further ingredients conventionally used in the field of cosmetics, such as preservatives, chelating agents, stabilizers, oxidation inhibitors, plant extracts, ultraviolet absorbers, vitamins, dyes, and fragrances.

Cationic Polymers

A cationic polymer is a polymer having a cationic group or a group capable of being ionized into a cationic group, and in general, an amphoteric polymer acquiring net cationic charge is also included in the terminology. That is, the cationic polymer is a polymer containing an amino group or an ammonium group in a side chain of the polymer chain, or a polymer including a diallyl quaternary ammonium salt as a constituent unit, and examples thereof include cationized cellulose, cationic starch, cationic guar gum, a polymer or copolymer of a diallyl quaternary ammonium salt, and quaternized polyvinylpyrrolidone. Among these, from the viewpoint of softness, smoothness and easy finger-combing during shampooing, and easy manageability and moisture retention during drying, and from the viewpoint of stability of the agent, a polymer including a diallyl quaternary ammonium salt as a constituent unit, quaternized polyvinylpyrrolidone, and cationized cellulose are preferred, and a polymer or copolymer of a diallyl quaternary ammonium salt, and cationized cellulose are more preferred.

Specific examples of the polymer or copolymer of a diallyl quaternary ammonium salt include dimethyldiallylammonium chloride polymer (polyquaternium-6, for example, MERQUAT 100; Nalco Company), dimethyldiallylammonium chloride/acrylic acid copolymer (polyquaternium-22, for example, MERQUAT 280, MERQUAT 295; Nalco Company), and dimethyldiallylammonium chloride/acrylic acid amide copolymer (polyquaternium-7, for example, MERQUAT 550; Nalco Company).

Specific examples of the quaternized polyvinylpyrrolidone include quaternary ammonium salts synthesized from a copolymer of vinylpyrrolidone (VP) and dimethylaminoethyl methacrylate, and diethyl sulfate (polyquaternium 11, for example, GAFQUAT 734, GAFQUAT 755 and GAFQUAT 755N (all by ESP Japan, Ltd.)).

Specific examples of the cationized cellulose include a polymer of a quaternary ammonium salt obtained by adding glycidyltrimethylammonium chloride to hydroxyethylcellulose (polyquaternium-10, for example, RHEOGUARD G and RHEOGUARD GP (all by Lion Corp.), POLYMER JR-125, POLYMER JR-400, POLYMER JR-30M, POLYMER LR-400 and POLYMER LR-30M (all by Amerchol Corp.)), and a hydroxyethylcellulose/dimethyldiallylammonium chloride copolymer (polyquaternium-4, for example, CELQUAT H-100, CELQUAT L-200 (all by National Starch and Chemical Company)).

The cationic polymer may be used in combination of two or more kinds. Furthermore, the cationic polymer gives better effects when the content is increased, but an excessively high content of the cationic polymer may cause stability failure and a decrease in the viscosity of the agent alone or during mixing. From this viewpoint, and from the viewpoint of enhancing the feel to the touch, the content of the cationic polymer is preferably 0.001 to 20 wt %, more preferably 0.01 to 10 wt. %, and even more preferably 0.05 to 5 wt. %, based on the weight of the conditioning composition.

Silicones

In order to improve the feel of use, the conditioner preferably contains a silicone. Examples of the silicone include dimethylpolysiloxane, and modified silicone (for example, amino-modified silicone, fluorine-modified silicone, alcohol-modified silicone, polyether-modified silicone, epoxy-modified silicone, or alkyl-modified silicone), but dimethylpolysiloxane, polyether-modified silicone and amino-modified silicone are preferred.

The dimethylpolysiloxane may be any cyclic or non-cyclic dimethylsiloxane polymer, and examples thereof include SH200 series, BY22-019, BY22-020, BY11-026, 22-029, BY22-034, BY22-050A, BY22-055, =2-060, BY22-08 FZ-4188 (all by Dow Corning Toray Co., Ltd.), KF-9008, KM-900 series, MK-5H, and MK-88 (all by Shin-Etsu Chemical Co., Ltd.).

The polyether-modified silicone may be any silicone having a polyoxyalkylene group, and the group constituting the polyoxyalkylene group may be an oxyethylene group or an oxypropylene group. More specific examples include KF-6015, KF-945A, KF-6005, KS-6009, KF-6013, KF-6019, KF-6029, KF-6017, KF-6043, KF-353A, KF-354A, KF-355A (all by Shin-Etsu Chemical Co., Ltd.), SZ-2404, SS-2805, FZ-2411, FZ-2412, SH3771M, SH3772M, SH3773M, SH3775M, SH3749, SS-280X series, BY22-008 M, BY11-030, and BY25-337 (all by Dow Corning Toray Co., Ltd.).

The amino-modified silicone may be any silicone having an amino group or an ammonium group, and examples thereof include an amino-modified silicone oil having all or a part of the terminal hydroxyl groups capped with a methyl group or the like, and an amodimethicone which does not have the terminals capped. A preferred example of the amino-modified silicone may be a compound represented by the following formula:

wherein R′ represents a hydroxyl group, a hydrogen atom or R^(X); R^(X) represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms; D represents R^(X), R″—(NHCH₂CH₂)_(m)NH₂, OR^(X), or a hydroxyl group; R″ represents a divalent hydrocarbon group having 1 to 8 carbon atoms; represents a number from 0 to 3; p and q represent numbers, the sum of which is, as a number average, equal to or greater than 10 and less than 20,000, preferably equal to or greater than 20 and less than 3000, more preferably equal to or greater than 30 and less than 1000, and even more preferably equal to or greater than 40 and less than 800.

Specific examples of suitable commercially available products of the amino-modified silicone include amino-modified silicone oils such as SF8452C, SS-3551 (all by Dow Corning Toray Co., Ltd.), KR-8004, KF-867S, and KR-8015 (all by Shin-Etsu Chemical Co., Ltd.); and amodimethicone emulsions such as SM8704C, SM8904, BY22-079, FZ-4671, and FZ-4672 (all by Dow corning Toray Co., Ltd.).

The total content of these silicones in the compositions of the present invention is usually 0.1 to 20 wt. %, preferably 0.2% to 10 wt. % and more preferably 0.5 to 5 wt. %, based on the weight of the conditioning composition.

Oil Component

For improving the feel upon use, the conditioner also may include an organic conditioning oil. The organic conditioning oil that is suitably used as a conditioning component is preferably a low-viscosity and water-insoluble liquid, and is selected from a hydrocarbon oil having at least 10 carbon atoms, a polyolefin, a fatty acid ester, a fatty acid amide, a polyalkylene glycol, and mixtures thereof. The viscosity of such an organic conditioning oil as measured at 40° C. is preferably 1 to 200 mPa·s, more preferably 1 to 100 mPa·s, and even more preferably 2 to 50 mPa·s. For the determination of the viscosity, a capillary viscometer may be used.

Examples of the hydrocarbon oil include a cyclic hydrocarbon, a linear aliphatic hydrocarbon (saturated or unsaturated), and a branched aliphatic hydrocarbon (saturated or unsaturated), and polymers or mixtures thereof are also included. The linear hydrocarbon oil preferably has 12 to 19 carbon atoms. The branched hydrocarbon oil includes hydrocarbon polymers, and preferably has more than 19 carbon atoms.

The polyolefin a liquid polyolefin, more preferably a liquid poly-α-olefin, and even more preferably a hydrogenated liquid poly-α-olefin. The polyolefin used herein is prepared by polymerizing an olefin monomer having 4 to 14 carbon atoms, and preferably to 12 carbon atoms.

The fatty acid ester may be, for example, a fatty acid ester having at least 10 carbon atoms. Examples of such a fatty acid ester include esters having a hydrocarbon chain derived from a fatty acid and an alcohol (for example, monoesters, polyhydric alcohol esters, or di- and tricarboxylic acid esters). The hydrocarbon group of these fatty acid esters may have another compatible functional group such as an amide group or an alkoxy group as a substituent, or the hydrocarbon group may be covalently bonded to those functional groups. More specifically, an alkyl and alkenyl ester of a fatty acid having a fatty acid chain having 10 to 22 carbon atoms, a carboxylic acid ester of an aliphatic alcohol having an aliphatic chain derived from an alkyl and/or alkenyl alcohol having 10 to 22 carbon atoms, and a mixture thereof are suitably used. Specific examples of these preferred fatty acid esters include isopropyl isostearate, hexyl laurate, isohexyl laurate, isohexyl palmitate, isopropyl palmitate, decyl oleate, isodecyl oleate, hexadecyl stearate, decyl stearate, dihexadecyl adipate, lauryl lactate, myristyl lactate, cetyl lactate, oleyl stearate, oleyl oleate, oleyl, myristate, lauryl acetate, cetyl propionate and dioleyl adipate.

Further suitable oil components are natural oils such as paraffin oil and natural triglycerides.

Suitable natural triglycerides are argan oil, shea butter oil, karite oil, olive oil, almond oil, avocado oil, ricinus oil, coconut oil, palm oil, sesame oil, peanut oil, sunflower oil, peach kernel oil, wheat germ oil, macadamia nut oil, macadamia oil, night primrose oil, jojoba oil, castor oil, soya oil, lanolin, passiflora oil, black cumin oil, borage oils, grapeseed oil, hempseed oil, kukui nut oil, and rosehip oil.

The organic conditioning oil may be used in combination of two or more kinds, and the total concentration is typically in the range of 0.1 to 20 wt. %, preferably 0.2 to 10 wt. %, more preferably 0.5 to 5 wt. %, based on the weight of the conditioning composition.

Alcohols

From the viewpoint of improving the sense of touch and stability, the conditioner may also contain a higher alcohol having 8 carbon atoms or more. Usually, the higher alcohol has 8 to 24 carbon atoms, and preferably 16 to 22 carbon atoms. Specific examples thereof include cetyl alcohol, stearyl alcohol, behenyl alcohol, and mixtures thereof.

The higher alcohol may be used in combination of two or more kinds, and the content thereof is typically 0.1 to 20 wt. %, preferably 0.2 to 10 wt. %, more preferably 0.5 to 5 wt. %, based on the weight of the conditioning composition.

Additionally polyols may suitably be comprised in the compositions. Examples of the polyalkylene glycol include polyethylene glycol and polypropylene glycol, and a mixture of the two may be used, or a copolymer of ethylene oxide and propylene oxide may also be used.

Cationic Surfactant

The conditioner may also contain a cationic surfactant. The cationic surfactant is preferably a mono-long chain alkyl quaternary ammonium salt, having a C₈-C₂₄ alkyl residue and three C₁-C₄ alkyl residues.

Preferably at least one mono alkyl quaternary ammonium surfactant is selected from the compounds with the general formula

wherein R₈ is a saturated or unsaturated, branched or straight alkyl chain with 8-22 C atoms or

R₁₂—CO—NH—(CH₂)_(n)—

wherein R₁₂ is a saturated or unsaturated, branched or straight alkyl chain with 7-21 C atoms and n is an integer of 1-4, or

R₁₂—CO—O—(CH₂)_(n)—

wherein R₁₂ is a saturated or unsaturated, branched or straight alkyl chain with 7-21 C atoms and n is an integer of 1-4, and

R₉, R₁₀ and R₁₁ are independent from each other an alkyl group with 1 to 4 carbon atoms, hydroxyl alky chain with 1 to 4 carbon atoms, or ethoxy or propoxy group with a number of ethoxy or propoxy groups varying in the range of 1 to 4, and X is chloride, bromide, methosulfate or ethosulfate.

Suitable cationic surfactants are, for example, long-chain quaternary ammonium compounds which can be used alone or in admixture with one another, such as cetyl trimethyl ammonium chloride, myristyl trimethyl ammonium chloride, behentrimonium chloride, trimethyl cetyl ammonium bromide, stearyl trimethyl ammonium chloride, stearyl trimonium chloride and stearamidopropyltrimonium chloride.

The cationic surfactant may be used in combination of two or more kinds, and the content thereof is typically 0.1 to 20 wt. %, preferably 0.2 to 10 wt. %, more preferably 0.5 to 5 wt. %, based on the total weight of the conditioning composition.

4. Hair Treatment Process

The hair treatment process of the present invention achieves a semi-permanent straightening of the hair, utilizing the acid of formula (I) such as glyoxylic acid as the active agent. The straightening effect of this process is not achieved by cleaving the disulfide bonds by reduction or the action of strong alkali. Accordingly, the usage of a reducing composition or an alkaline relaxer (lanthionization agent) is not required.

In step (a), the straightening composition is applied to the hair. The application weight ratio of hair to composition is 0.5:2 to 2:0.5, preferably 0.5:1 to 1:0.5, more preferably about 1:1.

Subsequent to the application, the hair straightening composition is left on the hair for 1 to 120 minutes, preferably 5 to 90 minutes, more preferably 10 to 60 minutes and most preferably 15 to 45 minutes at a temperature of 45° C. or below, preferably at ambient temperature (step (b)). Then, the straightening composition is optionally rinsed off from hair (step (c)).

In subsequent step (d), the hair is dried in order to avoid an excessive steam generation in the subsequent step of treating the hair with the iron. Typically, a hair dryer is used for this purpose, having a hot air stream at a temperature typically within the range of 60 to 140° C., preferably 60 to 100° C. The temperature refers to the temperature of the air stream on the hair.

Subsequent to the drying, the hair is treated with an iron (step (e)), A usual straightening iron may be used for this purpose. In order to prevent damage to the hair, the surface temperature of the iron is 250° C. or lower, preferably 230° C. or lower, more preferably 200° C. or lower. For achieving a good straightening effect, the temperature of the iron is 130° C. or higher, preferably 150° C. or higher, more preferably 170° or higher. The iron may preferably have a surface temperature of 180±50° C., more preferably 170 to 200° C.

After carrying out the straightening treatment described above, the cleansing and/or conditioning of the hair is performed with the cleansing composition and/or the conditioning composition as described in detail above, which comprise at least one compound of the general Formula (I) and/or a hydrate thereof and/or a salt thereof.

The hair cleansing composition may be used like a conventional shampoo. It is typically applied to the hair at a ratio of hair to shampoo usually in the range of between 1:0.05 and 1:0.5 and massaged into the hair for a time of 1 to 5 minutes at a temperature between 20 and 40° C., before it is rinsed off with water. Then, the hair may be dried with a towel. In case it is not desired to subsequently apply a conditioner, e.g., the one of the present invention or a conventional one, the hair may then be allowed to dry, optionally using a hair dryer.

The conditioning composition may be of the rinse-off type or the leave-in type, and can be used like a conventional hair conditioner. It is typically applied after shampooing the hair, preferably using the cleansing composition in accordance with the present invention.

The rinse-off type conditioner is usually applied to the still wet hair just after rinsing off the shampoo, but may also be applied to towel-dry hair. The leave-in type conditioner is typically applied to the towel-dry hair. In both cases, the conditioner is used at a ratio of hair to conditioner in the range of usually between 1:0.05 and 1:1 and massaged into the hair for a time of usually 1 to 15 minutes at a temperature between 20 and 40° C. A rinse-off type conditioner is then rinsed off the hair with water.

The conditions for the hair drying after using the shampoo or the conditioner are not particularly limited. The hair may either be allowed to dry at ambient temperature, or a hair dryer may be used, typically at a temperature of the hot air stream of 60 to 140° C., preferably 60 to 100° C. These values refer to the temperature on the hair. Suitably, the temperature can be determined in a contact-less thermal radiation measurement, e.g., by capturing the area where the hot air stream comes into contact with the hair with a thermal radiation detector such as an infrared thermometer.

In order to enhance the straightening effect, it is preferable to perform the drying with a hair dryer under continuous combing and/or with the hair being held in an elongated state using a brush or the like, for a time period of usually within the range of 1 to 15 minutes, depending on the amount and length of the hair.

It is possible to use only the cleansing composition and/or the conditioning composition of the present invention, e.g., in combination with a conventional conditioner and shampoo, respectively. For enhancing the effect of the present invention, however, it is preferable to use the cleansing composition and the conditioning composition in combination.

The cleansing composition and/or the conditioning composition may be used as the only shampoo or conditioner after the straightening treatment, or they may be used intermittently with a conventional shampoo and/or conditioner. For enhancing the effect of the present invention, it is preferable to use them as the only shampoo and/or conditioner.

By using the cleansing and/or conditioning composition comprising the compound of the general Formula (I) and/or a hydrate thereof and/or a salt thereof, the straightening and frizz-reducing effect of the process of steps process steps (a) to (f) can be substantially prolonged.

EXAMPLES

The present invention is now illustrated by the following non-limiting formulation examples and test examples.

Example 1 Straightening Composition

% by weight Glyoxylic acid 10%  Amodimethicone 1% Hydroxyethylcellulose 1% Sodium hydroxide q.s. to pH 1.5 Water to 100

Shampoo (Cleansing Composition)

Inventive Comparative (wt. %) (wt. %) Sodium laureth sulphate 10.0  10.0  Cocamidopropyl betaine 3.0 3.0 Sodium lauroyl glutamate 1.0 1.0 Cocoglucoside 1.0 1.0 Glyceryl oleate 1.0 1.0 PEG-18 Glyceryl oleate/cocoate 0.5 0.5 Lactic acid — 0.6 Glyoxylic acid 0.5 — Fragrance 0.5 0.5 Preservative 0.5 0.5 Water q.s. to 100 q.s. to 100 pH 2.8 2.8

In the cleansing composition according to the invention and the comparative cleansing composition, respectively, the content of glyoxylic acid and lactic acid was selected such that the molar concentration is the same.

Conditioner (Conditioning Composition, Rinse-Off Type)

Inventive Comparative (wt. %) (wt. %) Cetearyl alcohol 4.0 4.0 Cetrimonium chloride 1.0 1.0 Dimethicone 1.0 1.0 Glycerine 0.5 0.5 Lactic acid — 0.6 Glyoxylic acid 0.5 — Fragrance 0.5 0.5 Preservative 0.5 0.5 Water to 100 to 100 pH 2.5 2.5

In the conditioning composition according to the invention and the comparative conditioning composition, respectively, the content of glyoxylic acid and lactic acid was selected such that the molar concentration is the same.

Evaluation Test

Samples of frizzy hair (bundles of Indian frizz hair, untreated, obtained from IHIP, International Hair Importers & Products, NY; see FIG. 1, first photograph) were straightened using the above straightening composition.

The hair was washed with a conventional shampoo and after towel drying, the straightening composition was applied onto hair and left on the hair for 15 min at 40° C. Then, the hair was dried with a hair dryer. Afterwards, the hair was treated with a flat iron with a surface temperature of 230° C. Then, the hair was shampooed once again with a conventional shampoo (see FIG. 1, second photograph).

The post-treatment of the hair samples involved the application of the above-described shampoo compositions to the hair samples at a ratio of hair to shampoo of about 1:0.2, massaging the shampoo into the hair for 1 minute, followed by rinsing with water of a temperature for 37° C. for 1 minute. Then, the hair samples were dried with a towel.

To the towel dried hair samples, the above described conditioners were evenly applied at a ratio of hair to conditioner of about 1:0.5. The conditioner was processed on the hair for a processing time of 10 minutes at ambient temperature. Then, the hair was rinsed with water of a temperature of approximately 37° C. and dried.

This shampooing/conditioning cycle was repeated ten times with both the comparative compositions (see FIG. 1, third photograph) and the inventive compositions (see FIG. 1, fourth photograph).

FIG. 1 shows the results (from left to right: (1) untreated frizzy hair before the treatment with the straightening composition; (2) hair treated with the straightening composition and shampooed once with a conventional shampoo; (3) hair treated with the straightening composition after 10 shampooing/conditioning cycles with the comparative compositions comprising lactic acid; (4) hair treated with the straightening composition after 10 shampooing/conditioning cycles with the inventive compositions comprising glyoxylic acid).

As apparent from FIG. 1, the hair sample treated with the inventive shampoo and conditioning composition (far right) still exhibits a pronounced straightening and reduced frizz after 10 cycles, similar to the sample directly after the straightening treatment (middle left). For the sample treated with the comparative compositions, however, the straightening effect begins to vanish after 10 cycles, and frizz appears.

As a summary, it was observed that hair treated with shampoo and conditioner comprising glyoxylic acid was still straight, but the hair washed and conditioned with the comparative compositions was no longer straight and became frizzy again.

As a result, it was found that the process according to the present invention provides improved durability of straightening effect.

Formulation Examples

Straightening compositions, cleansing compositions (shampoos) and conditioning compositions useful for the process and the kit of the present invention are described in the following.

Example 2 Straightening Composition

% by weight Glyoxylic acid 5 Polyquaternium-37 0.7 Steartrimonium chloride 1.5 Dimethicone 1.0 Water to 100 The pH of the composition is 1.8.

Example 3 Straightening Composition

% by weight Glyoxylic acid 10 Hxdroxyethylcellulose 1.1 Behentrimonium chloride 1.5 Cocamide MEA 0.5 Dimethicone 1.0 Fragrance 0.8 Water to 100 The pH of the composition is adjusted to 1.9 with NaOH.

Example 4 Straightening Composition

% by weight Glyoxylic acid 10 Xanthan gum 0.7 Cocamide MEA 1.5 PEG-40 hydrogenated castor oil 0.5 Dimethicone 1.0 Fragrance 0.8 Water to 100 The pH of the composition is adjusted to 1.8 with NaOH.

Example 5 Straightening Composition

% by weight Glyoxylic acid 10 Polyquaternium-22 0.7 Cetrimonium chloride 1.5 Dimethicone 1.0 PEG-40 hydrogenated castor oil 0.5 Fragrance 0.8 Water to 100 The pH of the composition s adjusted to 2.0 with NaOH

Example 6 Cleansing Composition

% by weight Sodium laureth sulphate 10.0 Cocoyl betaine 3.0 Sodium lauryl ether carboxylate 2.0 Decyl glucoside 4.0 Polyquaternium-7 0.5 Glyoxylic acid 1.0 Sodium chloride 1.0 Fragrance 0.7 Preservative 0.5 Water q.s. to 100 The pH of the composition is 2.6.

Example 7 Cleansing Composition

% by weight Sodium laureth sulphate 8.0 Cocamidopropyl betaine 4.0 Sodium lauryl ether carboxylate 3.0 Decyl glucoside 5.0 Polyquaternium-7 0.5 Dimethicone 0.2 Glyoxylic acid 0.5 Glycol distearate 2.0 Panthenol 0.5 Sodium chloride 1.0 Fragrance 0.7 Preservative 0.5 Water q.s. to 100 The pH of the composition is 2.7.

Example 8 Cleansing Composition

% by weight Sodium laureth sulphate 8.0 Lauryl betaine 4.0 Plantaren PS 300 9.5 Glyceryl laurate 1.0 Polyquaternium-10 0.5 Dimethicone 0.2 Glyoxylic acid 0.75 Glycol distearate 2.0 Glycerin 0.5 Sodium chloride 0.9 Fragrance 0.5 Preservative 0.5 Water q.s. to 100 The pH of the composition is 2.9.

Example 9 Cleansing Composition

% by weight Sodium laureth sulphate 9.0 Lauryl betaine 4.0 Sodium lauroyl glutamate 1.0 Plantaren PS 300 9.5 Glyceryl laurate 1.0 Polyquaternium-10 0.5 Dimethicone 0.8 Amodimethicone 0.2 Glyoxylic acid 0.75 Glycol distearate 2.0 Glycerin 0.5 PEG-18 Glyceryl oleate/cocoate 0.8 Fragrance 0.5 Preservative 0.5 Water q.s. to 100 The pH of the composition is 2.9.

Example 10 Conditioning Composition (Rinse-Off)

% by weight Cetearyl alcohol 5.0 Behentrimonium chloride 0.8 Guarhydroxypropyltrimonium chloride 0.3 Quaternium-80 0.2 Panthenol 0.5 Glyoxylic acid 0.5 Fragrance 0.7 Preservative 0.5 Water q.s. to 100 The pH of the composition is 2.9.

Example 11 Conditioning Composition (Rinse-Off)

% by weight Cetearyl alcohol 5.0 Behenamidopropyldimethyl amine 0.8 Ceteareth-20 0.8 Dimethicone 0.2 Isopropyl myristate 0.2 Almond oil 0.2 Panthenol 0.5 Glyoxylic acid 1.0 Polyquaternium-37 0.8 Fragrance 0.7 Preservative 0.5 Water q.s. to 100 The pH of the composition is 2.6.

Example 12 Conditioning Composition (Leave-in)

% by weight Ethanol 20.0 Cetrimonium chloride 0.8 Quaternium-80 1.0 Almond oil 0.2 PEG-40 Hydrogenated castor oil 0.8 Glycerin 0.5 1,2-Propylene glycol 10.0 Glyoxylic acid 0.5 Fragrance, preservative q.s. Water q.s. to 100 The pH of the composition is 2.5.

Example 13 Conditioning Composition (Leave-in)

% by weight Ethanol 20.0 Behentrimonium chloride 0.8 Dimethicone copolyol 0.2 Argan oil 0.2 PEG-40 Hydrogenated castor oil 0.8 Panthenol 0.5 1,2-Propylene glycol 10.0 Glyoxylic acid 0.5 Fragrance, preservative q.s. Water q.s. to 100 The pH of the composition is 2.5. 

1. Process for semi-permanent hair straightening and aftercare treatment, which comprises the following steps, performed in this order: (a) application of a straightening composition onto the hair, (b) leaving the composition on the hair for 1 to 120 minutes; (c) optionally rinsing off the hair; (d) drying the hair, (e) treating the hair with an iron having a surface temperature of 130 to 250° C., (f) optionally rinsing off and/or shampooing the hair and drying; (g) treating the hair with a one or both of a cleansing composition and a conditioning composition, wherein the straightening composition has a pH of 4 or lower and comprises at least one carboxylic acid of the Formula (I) and/or a hydrate thereof and/or a salt thereof; the cleansing composition has a pH of 4 or lower and comprises one or more surfactants selected from anionic, non-ionic and amphoteric surfactants and at least one carboxylic acid of the Formula (I) and/or a hydrate thereof and/or a salt thereof; and the conditioning composition has a pH of 4 or lower and comprises one or more conditioning components and at least one carboxylic acid of the Formula (I) and/or a hydrate thereof and/or a salt thereof: R—CO—COOH  Formula (I) wherein R is selected from hydrogen, COOH, CN, optionally substituted C₁-C₁₀ alkyl, optionally substituted C₂-C₁₀ alkenyl, optionally substituted C₂-C₁₀ alkynyl, optionally substituted C₃-C₁₀ cycloalkyl, optionally substituted C₆-C₁₀ aryl or a 5-10-membered, optionally substituted heteroaryl group, wherein the optional substituents of the alkyl group are selected from halogen, hydroxyl, amino and C₁-C₄ alkoxy, and the optional substituents of the other groups are selected from halogen, hydroxyl, amino, C₁-C₄ alkyl and C₁-C₄ alkoxy.
 2. The process according to claim 1, wherein the carboxylic acid of Formula (I) in the straightening composition, the cleansing composition and/or the conditioning composition is glyoxylic acid and/or a hydrate thereof and/or a salt thereof.
 3. The process according to claim 1, wherein the straightening composition comprises the at least one carboxylic acid of Formula (I) and/or a hydrate thereof and/or a salt thereof at a concentration in the range of 0.1 to 40% by weight, preferably 0.5 to 30% by weight, more preferably 1 to 25% by weight, more preferably 2.5 to 20% by weight based on the weight of the total composition.
 4. The process according to claim 1, wherein the straightening composition has a pH of 1 to 3, preferably 1 to 2.5.
 5. The process according to claim 1, wherein the straightening composition contains less than 2 wt. % of sulfur-based reducing agents and is preferably free of sulfur-based reducing agents.
 6. The process according to claim 1, wherein the cleansing composition and/or the conditioning composition comprise the at least one carboxylic acid of Formula (I) and/or a hydrate thereof and/or a salt thereof at a concentration in the range of 0.1 to 5% by weight, preferably 0.2 to 4% by weight, based on the weight of the cleansing composition and the conditioning composition.
 7. The process according to claim 1, wherein the cleansing composition has a pH of 1.5 to 4.0, preferably 2 to 3.5 and/or the conditioning composition has a pH of 1.5 to 4.0, preferably 2 to 3.5.
 8. The process according to claim 1, wherein the cleansing composition comprises one or more anionic surfactants, one or more non-ionic surfactants and optionally one or more amphoteric surfactants.
 9. The process according to claim 1, wherein the cleansing composition comprises one or more anionic surfactants of the alkyl sulphate or ether sulphate type.
 10. The process according to claim 1, wherein the cleansing composition comprises one or more nonionic surfactants selected from alkyl polyglucosides of the general formula R₂—O—(R₃O)_(n)—Z_(x), wherein R₂ is an alkyl group with 8 to 18 carbon atoms, R₃ is an ethylene or propylene group, Z is a saccharide group with 5 to 6 carbon atoms, n is a number from 0 to 10 and x is a number between 1 and
 5. 11. The process according to claim 1, wherein the cleansing composition comprises one or more amphoteric surfactants selected from alkyl betaines and alkyl amido betaines.
 12. The process according to claim 1, wherein the cleansing composition has a total surfactant concentration of 5 to 50 wt. %, preferably 7.5 to 30 wt. %, more preferably 10 to 25 wt. %, based on the weight of the cleansing composition.
 13. The process according to claim 1, wherein the cleansing composition further comprises one or more conditioning components.
 14. The process according to claim 13, wherein the conditioning component comprises a cationic polymer and/or a silicone.
 15. The process according to claim 1, wherein the conditioning composition comprises one or more conditioning components selected from silicones, cationic polymers and cationic surfactants.
 16. The process according to claim 1, wherein the conditioning composition comprises one or more higher alcohols having 8 carbon atoms or more, preferably 8 to 24 carbon atoms, more preferably 16 to 22 carbon atoms.
 17. The process according to claim 1, wherein the conditioning composition is not rinsed off from the hair after application.
 18. The process according to claim 1, wherein step (g) is carried out repeatedly at least once a week, preferably at least three times a week.
 19. The process according to claim 1, wherein the cleansing composition and the conditioning composition in step (g) are used in combination.
 20. The process according to claim 1, wherein the straightening composition is applied to the hair in an application ratio of hair to composition of 0.5:2 to 2:0.5, preferably 0.5:1 to 1:0.5.
 21. The process according to claim 1, wherein the temperature of the iron is in the range of 150 to 230° C., preferably 170 to 200° C.
 22. The process according to claim 1, wherein the combination with the application of a reducing composition or an alkaline relaxer is excluded.
 23. Hair treatment kit for semi-permanent straightening and aftercare treatment of the hair, which comprises a straightening composition and at least one of a cleansing composition and a conditioning composition, wherein the straightening composition has a pH of 4 or lower and comprises at least one carboxylic acid of the Formula (I) and/or a hydrate thereof and/or a salt thereof; the cleansing composition has a pH of 4 or lower and comprises one or more surfactants selected from anionic, non-ionic and amphoteric surfactants and at least one carboxylic acid of the Formula (I) and/or a hydrate thereof and/or a salt thereof; and the conditioning composition has a pH of 4 or lower and comprises one or more conditioning components and at least one carboxylic acid of the Formula (I) and/or a hydrate thereof and/or a salt thereof: R—CO—COOH  Formula (I) wherein R is selected from hydrogen, COOH, CN, optionally substituted C₁-C₁₀ alkyl, optionally substituted C₂-C₁₀ alkenyl, optionally substituted C₂-C₁₀ alkynyl, optionally substituted C₃-C₁₀ cycloalkyl, optionally substituted C₆-C₁₀ aryl or a 5-10-membered, optionally substituted heteroaryl group, wherein the optional substituents of the alkyl group are selected from halogen, hydroxyl, amino and C₁-C₄ alkoxy, and the optional substituents of the other groups are selected from halogen, hydroxyl, amino, C₁-C₄ alkyl and C₁-C₄ alkoxy.
 24. The hair treatment kit according to claim 23, wherein the cleansing composition and/or the conditioning composition comprise the at least one carboxylic acid of Formula (I) and/or a hydrate thereof and/or a salt thereof at a concentration of 0.2% by weight or more, based on the weight of the cleansing composition and the conditioning composition, respectively.
 25. The hair treatment kit according to claim 23, wherein the cleansing composition comprises at least one anionic surfactant, preferably of the alkyl sulphate or ether sulphate type.
 26. The hair treatment kit according to any of the claim 23, wherein the conditioning composition comprises at least one cationic surfactant and/or cationic polymer.
 27. Use of a cleansing composition and/or a conditioning composition for the treatment of hair after a hair straightening treatment, wherein the cleansing composition has a pH of 4 or lower and comprises one or more surfactants selected from anionic, non-ionic and amphoteric surfactants and at least one carboxylic acid of the Formula (I) and/or a hydrate thereof and/or a salt thereof; and the conditioning composition has a pH of 4 or lower and comprises one or more conditioning components and at least one carboxylic acid of the Formula (I) and/or a hydrate thereof and/or a salt thereof: R—CO—COOH  Formula (I) wherein R is selected from hydrogen, COOH, CN, optionally substituted C₁-C₁₀ alkyl, optionally substituted C₂-C₁₀ alkenyl, optionally substituted C₂-C₁₀ alkynyl, optionally substituted C₃-C₁₀ cycloalkyl, optionally substituted C₆-C₁₀ aryl or a 5-10-membered, optionally substituted heteroaryl group, wherein the optional substituents of the alkyl group are selected from halogen, hydroxyl, amino and C₁-C₄ alkoxy, and the optional substituents of the other groups are selected from halogen, hydroxyl, amino, C₁-C₄ alkyl and C₁-C₄ alkoxy. 